PROJECT SUMMARY/ABSTRACT The goal of this Phase II SBIR project is to advance a new treatment for interstitial cystitis/bladder pain syndrome (IC/BPS) to clinical trials. IC/BPS is a chronic disease characterized by lower pelvic pain, urinary urgency and frequency, and urge incontinence. Chronic pain results from a disruption of the protective glycosaminoglycan (GAG) layer of the bladder wall, causing permeability and urinary leakage. There are few therapeutic options and approved treatments have met with limited success. Hence, the 4-12 million Americans suffering with IC/BPS face a lifetime of chronic debilitating abdominal pain and other symptoms. One promising treatment option to restore bladder impermeability is GAG replenishment therapy. However, the single chain, low molecular weight (MW) GAGs that are currently used do not properly mimic the proteoglycan- bound GAG layer of the normal urothelium, and response rates are low. Proteoglycans display multiple sulfated GAG chains in clusters, creating zones of high anionic charge and bound water. Glycologix has developed a novel and innovative family of high MW, branched biopolymers known as SuperGAGs that mimic the structure of proteoglycans. SuperGAGs have been designed to improve adherence to the urothelium due to their greater size, dendritic structure, and affinity for the bladder surface. In the Phase I project, synthesis and preclinical evaluation of first-generation SuperGAGs successfully demonstrated proof of concept for the preparation of large SuperGAG biopolymers (MW > 1MDa), and the ability of these biopolymers to restore bladder impermeability and reduce visceral pain in a well-characterized rat model of bladder permeability. This result was confirmed in a second model in which bladder permeability was induced through an inflammatory process and bladder permeability was quantified using magnetic resonance imaging (MRI). In this Phase II project, Aim 1 is to synthesize and characterize a small number of SuperGAG derivatives bearing targeting ligands and other groups known to enhance binding to the bladder wall using methods validated in Phase I. Aim 2 is to compare the effectiveness of these biopolymers in a well-established mouse model of induced IC/BPS in which bladder permeability is induced by inflammation. Quantitative contrast- enhanced MRI will be used to measure restoration of bladder impermeability. The SuperGAG with the longest adherence time, tightest binding and most effectiveness will be selected for clinical development. Aim 3 will initiate development of the SuperGAG clinical candidate by executing required GLP safety studies and GMP synthesis in concert with input from the FDA. At the conclusion of the Phase II project, Glycologix intends to submit an Investigational Device Exemption with the FDA to gain approval for initiation of human clinical trials of SuperGAG Bladder Instillate as a new medical device treatment option for patients suffering with IC/BPS.